SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52ba31a79f97d7d3011944338e4ebb265e85904c6530eff6dc20747baf178389' 
  AND token = 'I3+i554jVjDcmD/vN9AQ8vUCbsvtVJqlVFUGHjs74p4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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