SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18d8ccdde98c499b410d873c15c33035ee4a643d3b20925876d7c2ec51c76df7' 
  AND token = 'DRzLRsGVtd0oyDzOdZK7ah9D2Bxj09NvWcVNKWhnBOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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