SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a0fa5525640e06c847c804055d8e6cc1f7e23282e4476de2f914e827d3eb12b' 
  AND token = 'WRIjnzwYAlyJjSnEYGudMSZhPVMKYHrrNF/BsTp3TbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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