SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd58edcdc310a784c98f726cfd0f3bd34c2ad1b5784c7d1902be60d930f6db263' 
  AND token = '5x0tyUCPiqHoTl5rRLu2YJQ4Pd8gaugHfrmY8mBFwhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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