SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba412dc32180b1b33c1f8286d7ab5b0345fe75756e748ae3fb3f9383b3d5b679' 
  AND token = '6E9/LB5w6+MWvCtrLVAFwE8yEPjjeK/tfvqNdDEqzJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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