SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64504e4740782144aee4c5d1bd5b3002da1ce6d118e0af00b18bec07e68c726a' 
  AND token = '9dbA1MFpAlu/yyLtN0eFVWOzpcbGCy7zHETVgDVlPNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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