SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea6b5624be916f5f1ac43f273664212d0753bc94732c30b89b6ecb7ff2c69c71' 
  AND token = 'vP2QpkwJOXU6hVm2utsKGBYviWT/a5xyV2EMW8tHm50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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