SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f187c3ddee0d5908df7e1d963142b97528afdba43fcef475ea3a53e0111306b5' 
  AND token = 'tjOFZsjABWlFkw76K831yM1MzKwblUVzwnMr5vlCCyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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