SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aca7268f761a0ed8d1f919c3b925bb9c2f0227579fc2144ff1cbe466949c9b72' 
  AND token = '7v6Ct0qS4/X0JkWJvDGZ7gctg9b1JOfBonPiVhVCwSs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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