SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87cdb46720cefb464d23f1ebc68de2d306f09f846893d2e829356ad3d8125edf' 
  AND token = 'EoV7LoDghIyCwxhJTFJzWMU4kuHqn0NsXovTkowTkyQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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