SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7474c824214193aef530acc32018b4226f0b377e79db958b3c714eec8b7244a0' 
  AND token = 'R+uxsrtcqgVv8zvKJOjphDq3v4cdaIJgVaQHkuwYm6o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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