SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0c98875df4590f8a792f8dfaf38692b3038334744ec818b35dd19f2b8724b0f' 
  AND token = '2VluihZFNThmhz7UJ+y+PFh6q9QTt5du4fhixL0gvKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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