SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '116096956025653fc871c172f2888da1a19d4ce1b548e430ce51408681f3f333' 
  AND token = 'BBnjBgnIK8/UTDnMw8hNGiSIsL2bnVRf/0FU8wP6CJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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