SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f6b555f8f9206476d3c9c1a3e6fb89ab74b5678fc428606f8bb3b728170db1b6' 
  AND token = 'QPk3wmEW/dD6YSGRFGKfZLbf92A2+jGFPjqn6Tur1PI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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