SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ebaa2696f7fc1f702b475110c72f99e2f680bffad9583381750e8618b6f7f06' 
  AND token = 'D/V+kiuScvsHJwTjDBibwlgSfhEjYZ7y19tfjhxDgpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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