SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a08696708d6b9aac8212687ad9151c42a63f1cf70460e0ffe1f4e28a8389ff55' 
  AND token = 'QmQUl9AFUv/FSkPoO8o16N1v26ivamBUC1KCUP/IwIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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