SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20f513cf5bff3bff72c5bface1ae9debd6a49bb3c52e55379db47dae6f395073' 
  AND token = 'n9qNSHPraubC3d4F+c5xdbCOo+mOlLDulIAyS25TApA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}