SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1efdf5182dedbeffdcc44b78bc219fe65412641b6b79cd32e508350a4e226b24' 
  AND token = 'PwKdHKVrsazQWFXBqosIYXkeEIOiFwINepy7RIWFIXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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