SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2556c1020e9c8b1e19502330e5418f2a735e766e5dd60825a80d0c9891f3089' 
  AND token = '20QK1Pdu2gyknidmcAi/m/vudx3MHQlLTG9mBo/RAs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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