SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4f6d86f480db169407dc3ae225972315e594b94c48115f3894e804a2cf2899b5' 
  AND token = '/SBsAek+sR6oHVx4swP5+2dIWVbnIi5KmU3eSEVjeCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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