SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4c97ff593848666bc84f5b9af734d4da9ae69aa2e1d9ff5e62be648efbb7e69' 
  AND token = 'eY6cFvp8OH+zK89rwiXNOF08zCZIbqSGO56Lx2DzIKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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