SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a7469d9747285f7c2d53060b36584cdc7553b478f0b033bad52fe3b24e533ac' 
  AND token = 'jmLx+fdvp12O/XdzqV9GHPaAohMipkJoEnmvO6zAcVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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