SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59db45d473fd227cb875efa37999fdf7539ad8381fdffbabc340f285f8dbda39' 
  AND token = 'DJ/tcHIW+5BAnrn3S/CkeV1svyQrDJY/MGh9BA+yAlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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