SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0736b0eee1e391b34ccd7b8633639ecc5271841122eb5bf582e19c7b207b8e7' 
  AND token = 'x9oiocuqSVuYPsCeWkI/Xqkqk4U0PtbEjOAW+9yEA0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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