SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a083bc9b69f80053caf569f0ed59f5f546a6abe4e95d46ffac6a1899de503d18' 
  AND token = '08gfngh13J7hMsRelMUU9/scwlG3Q0QyYZYObi/oyaI=' 
  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"
    }
  }
}