SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46cbdfba183b3cd74ecd76f9b3c9416fa2665e2289cac9b8179941a05ca13815' 
  AND token = '4EVWChCDOBzsdoEjETKSbLqmIyB03tRwNhyqq6+TLZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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