SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33bf19d2628d0c67b357fff8cd6ebffda711462fe85b4665db559bd535b575ee' 
  AND token = 'IgZcLR1D6qvZEC8NJ/o62xqI8WGYPYjGb1W9hfM6Knk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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