SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78587c772bccc3da01640d5581ac7259abaf90f6a4dac95ca425a3d75c122e7e' 
  AND token = '8CgxhvFNN02vs9QJnrvMoNul8UjJSeKCHkqMCJVCwmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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