SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c569f09aeb414fe9bd89445759660f2d1d58efda116e1379685c496224ba30bb' 
  AND token = '4rEApiW2W2qsYu7aPocEgNYMVYMjz74/TiYfix64bAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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