SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09534cba99d7e29530670b55948cdfd874ff31eaf766c5e8841ef10f86ddb4a4' 
  AND token = 'LU0Z5BxumWbJiqTxQGGTyvuOh2STtkZsLlD7Ij/+6tM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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