SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75090f22059a19e7dc75bf231de23ae701f3300a4ce930f5f937e916c8d71e6e' 
  AND token = 'mnhQzPdQGpB/LVCsoPgxLVFc7ThiwZ42FAEOGW2L+QY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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