SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14bbc9d3b9e0a1bc700ef3c7ca2ba2d85c4e87709aeda95e64222757c55266e8' 
  AND token = 'gaQKIpNFphu+5zq/Yb8iCTtUfA7pzB/1jRTP8lwDP0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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