SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dc1972855b42ab81cf1077f9de1657f9ade1d723b933fce07a96ad2f0f512031' 
  AND token = 'fzaIIGql3D6JnTNRY1JO8lEdGw8HjxmmOL+PDsH7Wfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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