SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49ad716987d51191fe1055b7c8585a54319216d3f59a8f7d2bbec706a38590d0' 
  AND token = 'zl1jG7BxyWeBViCPRan+WaznOnE0R1VqMfvOMek0XY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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