SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7c5f9afc66c6b5ae9b050f344b4aa45d18626fef700365a59c05303b69a91ac' 
  AND token = 'EBDCyXWFSveLNQl21ax62ENNIP/SBtjITTSPlpNbJAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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