SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c87bf6799c5d1d611ffa9696a38f8a0c853e57f81c89cdfe83b4c83669adf5c1' 
  AND token = 'ZdikfkAusYSaojuuxhswCtxShulaWeoBeCJz1I4Ds80=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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