SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a67510e8480342b1a057cc27b0f85fce33e3e76b92b8d491c7586ecb682f7a6' 
  AND token = 'KlalGnvKqaYgBenj4a+gGAWiTk6HD8L12XhvFO/tJAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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