SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c0dfd6e74633470d5467c668e12df00d590f781194d73be0609fe85936bb9bf5' 
  AND token = 'VqiZQ+fTw0FOzv+4I1sm3pysfoEeTSZTiL9Z2DGxO6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}