SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9efc0b5f9217d9fd2b77755a2049026d928d5cc363eb335697884340f0398ef2' 
  AND token = 'gNaaNY/h2W+Z3oDAjzTGrCc8Jl6z+D/RhX12XoaG6rI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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