SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8aa24c9105f741cee37515ceb51ed34a17bea0c2a980caa64d3b6f9438276837' 
  AND token = 'bfo8XXn8ycTJ0P+rAT5BwQjt8kjclulY41dOsOQuork=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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