SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50e45013c7d2332eb8ca60a6dcff46a29619315f0f8386c08cb2388d5adbd1bb' 
  AND token = 'ipEMZYf7wgJxh9ft0Jgk0Et3yBKjeSeOvMgHa3jRSDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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