SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd7affa5c276af57490dd10ff2cc615b89b21bca3b7d4e10e3b94a687dac552f' 
  AND token = '2m2YK8YCQcf0QMm07SX/5OpltYS/cqs+LKrIEm6Dx+k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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