SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '547b51a5a2146b25c3403099813b003dfe3a09dd158a771fde10c438e490d670' 
  AND token = 'BFi+VekJKpbgfu/Xdq3tX7qxcEp7jif/CKSH9PbFEpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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