SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e318eb38d56bedb0d989861629195d692f45ae045ddcc1870c06a85f53f30430' 
  AND token = 'hW8iHGUzGTwjA7G9GqP5ffA4AkCZX87lCcD3PKgFfBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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