SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbc126aede4ac0974d4383f40ed5a611722e1fab6fabb76fab515f6c7bf6579c' 
  AND token = 'Qx633B9EgJ74TWGDHeopnjwzxoh3I9CUCIHWdtnOOdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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