SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ad2f74bf95bfa6fe63609fa776269ef12a1e2ef7335c456265a1c4736d54fc6' 
  AND token = 'Tmi0TyB34ZFZmHwvj2iP+k1FSVMxSEdAfjHHgiScF6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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