SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cee212659b0ecaf1967442c379a867eb7b5d307389d6249c6fb27d40f6f7005' 
  AND token = 'GKdKVVmu1ntUdvmv3mJEs+gxKSjFqG4EUt5w47ypsM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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