SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f5d209eb156c19b1f559c09987c3a93e54704e4daf95ad3290ced61ac1d7c1a' 
  AND token = 'qkxKQGpsQK+fUjGDpCF+7Zg2IJvGmpXEwmXXZSLaWWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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