SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '428acf082f190ae07a8e4d97644f123d2a9425ef637e3c0130152d68f8669441' 
  AND token = 'tD15Fjqe0u7bnlTvkkOhyzYPjW6T0noN/CilRwRiqEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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