SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8014ed5282868a162e2a37c6e82afcbd6343aeb82e2fa1b48a731c4ee990340' 
  AND token = '7PAvbIcfwMGzxhC9j0O0sb1YfkvX8BpDc6rPn/3S4kY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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