SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '466fa694f35201196cdd3a21c561d254ff1ee9c7bcf265fbe43e31060fb181bd' 
  AND token = 'fQnr8MlhTIGzUNBP+CNDxCv9HralOgVjTQAm+kgwgo4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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