SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '35c842f288276760b7c822d38bd3c7d0b8a9dd174c5d0820f98eeb39307e32eb' 
  AND token = '0uiFZMJ+7L5qpEAPUoU5JuhPYCXm2HdVW7URVf66/Nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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