SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '949b8c1d20ff94167770225d060e47f525b0ba20b6d4c9b11a6cb622b097a44e' 
  AND token = 'MPTq6A9TzLu0AN46FjOaC56iW63Ve18bfPVgLsILULU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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