SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c11ee74a427098736d434d9fa97047e233ebeef6fc5b1293bb174320beafff93' 
  AND token = 'jI6kZL8x4pnCmYkb/dsWgIDrK5z6P1Y7VN4xg8uXaM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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