SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e58d4892f6dba136415162fa2572bbf20ea6ce89b3c8df2351e7993f71d9d43' 
  AND token = 'MZZl1BLlMoHIeaBOlXsU90lhHA/q0ROelI5d1HhphoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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