SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3245d6b4f0f7ce168cd5583bef26a2923ecbdcc3701ba4747aae387a574891a' 
  AND token = '2PNPRwv1zgZM+99yIWV1BwhR+2pNapKx5yUVHWpu7ho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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