SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a53117c8da1c5c16e3a6cffb611251b18ea2df31919d5e9a075afa6930b988f0' 
  AND token = 'o4POMbMqEYuynDu7BIL9U4rTNuek4NLpqfcQtWraFuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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