SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4fc68c2a3f5fcaff3c2685f0ec2709bd038c05f56ede3c789a748ee318b305e' 
  AND token = 'HLBpW2U10GKTF/MOY5CwVj23ouTxGfkSZCglD/PzjPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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