SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eaba408e902ea185f914307017a40b048978e7a74fd7a1d968a729d9ad3ba50a' 
  AND token = 'Ddh98LLiYjA/TVYxbGozhmiy3WNBjPQdrXdu/5oBtTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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