SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '293dd3c525e1c42e3e610fefac0b94278f35910212a841f5f4762657d26a08bc' 
  AND token = 'WNxAHwq96c30YY6CtCEegpOiPq8EOq5AxSRu396Rwv4=' 
  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"
    }
  }
}