SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73feca6d7c3a1cf6ad62fd738edce47c65caea420fbbd0690a4b8d962a79af1c' 
  AND token = 'zZWVQLoUwkx3+j4WFZUKvkBcTpApog1m+Z8cJ+GLMKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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