SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82a1ad9685fc3aa4f398df92bbb769e0344326136b99f8520466035c559bd3d4' 
  AND token = 'ZcmRDuTnYlGXfIrxjGO2nQ4B+fQPw2n5Vjg0B9U3CI4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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