SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e872da65fe835cb6d50573f99ef119610bdc942d78284d068c40f709a0181bd' 
  AND token = 'LWw70BAOshqDLEzJKB+N/u/21awErKCGhenCNKEO80E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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