SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e2ab3b661dbcb5c4f2f5adc7094a1d06d86d21aef8bfef1980e56c94a98ab80' 
  AND token = 'jl0F7j63yaw1rMZiIaiTlPOOp7kchgA/KTL0BSUNbo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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